import 'package:flutter/material.dart';
class Test26 extends StatefulWidget{
    _TestState createState() => _TestState();
}

class _TestState extends State<Test26> {
    
    bool _visible = true;

    @override
    Widget build(BuildContext context) {
        return new Scaffold(
            appBar: AppBar(
                title: Text("test26"),
                centerTitle: true,
            ),
            body: Container(
                child: AnimatedOpacity(
                    opacity: _visible ? 1.0:0.0,
                    duration: Duration(
                        milliseconds: 1000,
                    ),
                    child: Container(
                        width: 300.0,
                        height: 300.0,
                        color: Colors.deepPurple,
                    ),
                )
            ),
            
        );
    }
}
